1. Field of the Invention
The present invention relates to a technology for estimating the data volume of a digital book.
2. Description of the Related Art
Conventionally, a technique has been proposed in which pages of a book are turned to be photographed by the camera of a tablet terminal or a smartphone terminal and thereby digitized without being cut. However, when a book is opened and photographed from above in a normal state, character strings and diagrams in an image acquired thereby are distorted due to the curl of the pages of the book. That is, this unprocessed image that has just been captured is not suitable for reading.
Accordingly, a technique has been proposed in which, after image capturing, image data acquired thereby are subjected to digital book creation processing, such as color conversion, shape correction including curvature correction, trapezoidal correction, and rectangular correction, and compression processing by a tablet application so as to be converted into images that are easy to read (for example, Japanese Patent Application Laid-Open (Kokai) Publication No. 2014-140146).
When a captured image data group that has not been subjected to any processing is processed to be a digital book so as to be easy to read, its data volume is increased or decreased (generally decreased). However, this digital book creation processing including image processing such as color correction and shape correction requires a long processing time. In addition, the volume of data subjected to the digital book creation processing varies depending on the characteristics of the page images. Accordingly, a technology has been demanded by which the data volume of a digital book to be created can be estimated.